Problem: Solve for $x$ and $y$ using substitution. ${3x-2y = -8}$ ${x = y-1}$
Since $x$ has already been solved for, substitute $y-1$ for $x$ in the first equation. ${3}{(y-1)}{- 2y = -8}$ Simplify and solve for $y$ $3y-3 - 2y = -8$ $y-3 = -8$ $y-3{+3} = -8{+3}$ ${y = -5}$ Now that you know ${y = -5}$ , plug it back into $\thinspace {x = y-1}\thinspace$ to find $x$ ${x = }{(-5)}{ - 1}$ ${x = -6}$ You can also plug ${y = -5}$ into $\thinspace {3x-2y = -8}\thinspace$ and get the same answer for $x$ : ${3x - 2}{(-5)}{= -8}$ ${x = -6}$